1. Field of the Invention
Exemplary embodiments of the present invention relate to a communication system; and, more particularly, to an apparatus and a method for transmitting data using a Repeat Accumulate (RA) coding scheme in a communication system.
2. Description of Related Art
Intensive study has been performed to provide users with services having high transmission rates and various levels of Quality of Service (QoS) in the next-generation communication system. Specifically, various data coding schemes have been proposed to transmit various types of a large amount of data at a high rate using limited resources in the next-generation communication system, and those schemes should support various coding rates.
A Forward Error Correction (FEC) coding scheme has been proposed as an exemplary coding scheme for supporting various coding rates during high-rate transmission of a large amount of data in a communication system, and a RA coding scheme has been proposed as an example of the FEC coding scheme. The RA coding scheme provides good performance and code gain using a RA coder of a relatively simple structure, and is widely used for data transmission. According to the RA coding scheme, the number of repetition can be increased, during RA coding of data to be transmitted, so as to generate a RA code having a low coding rate.
However, the above-mentioned RA coding scheme has a problem in that, when a RA code having a low coding rate is generated during data transmission using the RA coding scheme, the performance degrades at a low coding rate, e.g. at a coding rate of ⅙ or less. In other words, when data is transmitted using the currently proposed RA coding scheme, the Bit Error Rate (BER) of the transmitted data increases abruptly as the coding rate decreases, specifically at a coding rate of ⅙ or less. As a result, during high-rate transmission of a large amount of data at a low coding rate using the RA coding scheme, the amount of data transmitted normally decreases rapidly, which means that the amount of data to be retransmitted increases (i.e. data transmission rate decreases), finally degrading the system performance.
Therefore, there is a need for a scheme for transmitting data using the RA coding scheme in a communication system without exhibiting performance degradation either in a high coding rate or in a low coding rate.